FDA scrutinizes AED manufacturing processes
The FDA will hold an advisory panel meeting on Jan. 25 regarding regulatory classification of automated external defibrillators (AEDs) to either reconfirm to class III, which is subject to premarket approval application, or reclassify to class II, which is subject to premarket notification, or 510(k).

The FDA classifies medical devices into one of three categories based on the level of control necessary to provide reasonable assurance of safety and effectiveness. The classification process is a risk-based process that allows the FDA to apply the appropriate level of regulatory oversight before devices are marketed. Class III devices are those requiring the greatest level of control due to their life-saving impact, their potential for injury or lack of information about how to control the device's risks.

AEDs were given a class III designation when they were determined to be substantially equivalent to similar class III devices that were on the market prior to the 1976 Medical Device Amendments. However, they have always been regulated through the 510(k) process, a premarket pathway that is typically reserved for class I and class II devices, but which also has been used for some class III devices.

Last November, Jeffrey Shuren, MD, director of the FDA's Center for Devices and Radiological Health (CDRH), sent a letter to manufacturers of AEDs about developing safer products.

Shuren noted an increase in recalls and medical device reports (MDRs) regarding AEDs over the last five years. From Jan. 1, 2005 to July, 10, 2010, there were 68 recalls, exhibiting an increase from nine in 2005 to 17 in 2009, the last completed year for which data are available. During this period, the FDA also received more than 28,000 MDRs, an increase from 4,210 in 2005 to 7,807 in 2009. The FDA conducted multiple inspections of all external defibrillator manufacturers throughout this period, Shuren wrote.

As a result of these problems, the agency "may, in the future, take regulatory steps to improve the current premarket and postmarket regulatory processes associated with external defibrillators," Shuren wrote, adding that such steps "will help mitigate current risks and reduce future risks associated with external defibrillators."

He said that many of the problems are preventable and that there are "numerous problems with industry practices for designing and manufacturing defibrillators, handling user complaints, conducting recalls and communicating with users."

To date, the agency has addressed individual device problems on a case-by-case basis. "However, our analysis of MDRs, recalls and inspections confirms that common problems persist across all types of external defibrillators and all manufacturers. Therefore, the FDA is taking steps to address these pervasive issues on an industry-wide basis," according to a white paper published by CDRH.

The white paper said that manufacturers sometimes use design practices that lead to inconsistent device performance. For example, a firm designed its voltage-monitoring circuit to draw power from the same power source it was intended to monitor. "Because of this design, a momentary drop in the voltage caused a false signal to shut down the AED and the device was unable to deliver a shock, which may have caused a patient's death."

It also cited problems in how manufacturers test and incorporate components used in the manufacture of AEDs, as well as how they evaluate changes to the device before they are implemented. In fact, between 2005 and 2010, the FDA issued nine warning letters to external defibrillator manufacturers, seven of which cited the firms for failing to appropriately control these aspects of their manufacturing process.

The report from the CDRH noted that manufacturers have used a "fix-on-fail" strategy to deal with the problems, which refers to the practice of identifying and trending problems on a case-by-case basis and repairing individual devices rather than communicating the problem to all users as part of the recall process.

According to a 1990 amendment to the 1976 Medical Device Amendments, the FDA must either down-classify AEDs to class II or keep AEDs as class III and require they go through the more stringent PMA process.

A final decision about the classification and regulatory pathway for AEDs is anticipated to be published this year.